Electrode Characteristics of Nanostructured Mg2Ni ‐ Type Alloys Prepared by Mechanical Alloying

A mechanical alloying process is introduced to produce nanocrystalline metal hydride. The mechanical alloying process has recently emerged as a novel technique for producing alloy powders whose structures are nanocrystalline. alloys were prepared using planetary ball mill starting from mixtures of elemental powders. Nanocrystalline alloys were obtained by both the long‐term ballmilling (mechanical alloying) and heat‐treatment of the ballmilled powders. In comparison with the polycrystalline material, nanocrystalline showed a lower temperature for hydrogenation and a higher discharge capacity at 30°C. The partial substitution of Cu for Ni increased hydrogen absorption and desorption at 200°C and greatly improved the discharge capacity of the nanostructured electrode at 30°C. The discharge capacity of the 120 h milled electrode was 350 mAh/g. © 1999 The Electrochemical Society. All rights reserved.